/*
 * Copyright 2010, Andrew M Gibson
 *
 * www.andygibson.net
 *
 * This file is part of DataValve.
 *
 * DataValve is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * DataValve is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with DataValve.  If not, see <http://www.gnu.org/licenses/>.
 */
package org.fluttercode.datavalve.params;

import java.io.Serializable;
import java.util.ArrayList;
import java.util.List;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

/**
 * Splits the query line based on a regular expression.
 * Override {@link #getRegEx()} to change the regex used to find parameters.
 * The default is to split based on <code>:name"</code> or <code>#{name}"</code>.
 *
 * @author Andy Gibson
 */
public class RegexParameterParser implements ParameterParser, Serializable {

    private static final long serialVersionUID = 1L;

    private Pattern pattern;

    protected Pattern getPattern() {
        if (pattern == null) {
            pattern = Pattern.compile(getRegEx());
        }
        return pattern;
    }

    private String getRegEx() {
        return ":[A-Za-z0-9\\_]+|#\\{.+}";
    }

    @Override
    public String[] extractParameters(String line) {
        List<String> parameters = new ArrayList<String>();

        Matcher matcher = getPattern().matcher(line);
        while (matcher.find()) {
            parameters.add(matcher.group());
        }
        // if we have params, return them as an array
        return parameters.toArray(new String[parameters.size()]);
    }
}
